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Trouble running code on Windows [message #870853]

Wed, 09 May 2012 19:22

Eclipse User

I have a bit of a strange issue. I am developing an application using the WindowBuilder and associated libraries. The program works great on my 32-bit Linux box that I have been developing on. However I have two issues.

1) When running the jar on a 64-bit machine, it fails, which makes sense because I packaged the 32-bit libraries in the jar. If someone knows how to make the jar dual architecture, help would be greatly appreciated.

2) More importantly (as my client is chiefly 32-bit Windows XP as most of the world is) I can't run it on Windows. I actually moved the project over to a windows box, set up the WindowBuilder libraries in Eclipse, and recompiled, and it did work. However when I try to use my jar created in Linux, it fails with a message that I will attach (something about needing swt_gtk libraries). Now I'm somewhat new with java, but isn't the goal interoperability? I just find it strange that WindowBuilder seems to be using platform specific code. That being said, any ways around this (ways to make the program work on multiple operating systems) would be fantastic.

Sincerely,
Jesse

Also, I had posted this in the WindowBuilder section, but they sent me here. So my apologies for the duplicates.

Re: Trouble running code on Windows [message #871028 is a reply to message #870853]

Thu, 10 May 2012 10:51

Eclipse User

Hi there Jesse, you need to download the swt jars for each operative system. Java is portable, but SWT not totally.

Re: Trouble running code on Windows [message #871116 is a reply to message #871028]

Thu, 10 May 2012 19:01

Eclipse User

How would you go about doing that in Eclipse? Thanks

Re: Trouble running code on Windows [message #871295 is a reply to message #871116]

Fri, 11 May 2012 15:23

Eclipse User

On 5/10/12 7:01 PM, Jesse Osiecki wrote:
> How would you go about doing that in Eclipse? Thanks

You have 2 basic choices:
1) Package separately for each platform (win32/win64/gtk32/gtk64/etc)
Not too difficult with a little ANT-fu. It does mean you then have
multiple platforms end products. This is the route Eclipse itself has taken.

2) Package all the different platform jars and decide at runtime which
set to load.
There are some tips on how to do this here:
http://stackoverflow.com/questions/3959556/problems-with-loading-resources-during-execution

This is how I've tackled the problem. Each SWT platform jar goes in its
own subfolder win32\win64\etc. The main class detects which platform its
running on and then creates a new classloader with URLs that include
that subfolder in the path. It then launches the rest of the application.

All this is packaged up into one runnable jar using ANT.

Re: Trouble running code on Windows [message #871311 is a reply to message #871295]

Fri, 11 May 2012 17:26

Eclipse User

I'm messing with that code given in the error trying to get it to chainload my program. Two questions.

1) What does your ant build script look like?

2)I have completely forgotten and will probably ask later Cool

Re: Trouble running code on Windows [message #871578 is a reply to message #871311]

Mon, 14 May 2012 09:04

Eclipse User

Attached are the build.xml and the main starting class

I've modified them slightly from the ones I actually use to remove any
possible reference to stuff I do for work, so there might be some typos
in there.

It should all be fairly obvious, let me know if you have questions.

In the build I'm currently only packaging for Win32/64. Its obvious and
easy to expand to all SWT platforms.

On 5/11/12 5:26 PM, Jesse Osiecki wrote:
> I'm messing with that code given in the error trying to get it to
> chainload my program. Two questions.
>
> 1) What does your ant build script look like?
>
> 2)I have completely forgotten and will probably ask later 8)

package com.andi;

import java.io.InputStream;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.Properties;

public class Main {
private static final String LAUNCH_CLASS = "com.andi.TheRealMainClass";

public static void main(final String[] args) {
final String osArch = System.getProperty("os.arch");
final String osName = System.getProperty("os.name").toUpperCase();

final boolean is32bit = !osArch.contains("64");
final boolean isWindows = osName.contains("WINDOWS");
final boolean isLinux = osName.contains("LINUX") || osName.contains("NIX");
final boolean isMac = osName.contains("MAC");

String path = "";
if (isWindows)
path = "win";
else if (isLinux)
path = "gtk";
else if (isMac)
path = "mac";
if (is32bit)
path = path + "32";
else
path = path + "64";
System.out.println("Selected SWT classpath platform: " + path);
final ClassLoader parent = Main.class.getClassLoader();

final ArrayList<URL> urls = new ArrayList<URL>();
try {
final InputStream stream = parent.getResourceAsStream("libjars.properties");
final Properties properties = new Properties();
properties.load(stream);
stream.close();
String libs = (String) properties.get("contents");
for (final String aLib : libs.split(";")) {
urls.add(new URL("jar:rsrc:lib/" + aLib + "!/"));
}
libs = (String) properties.get("contents." + path);
for (final String aLib : libs.split(";")) {
urls.add(new URL("jar:rsrc:lib/" + path + "/" + aLib + "!/"));
}
} catch (final Throwable e1) {
}

try {
if (urls.size() > 0) {
final Method m1 = parent.getClass().getDeclaredMethod("addURL", URL.class);
m1.setAccessible(true);
for (final URL url : urls) {
m1.invoke(parent, url);
}
for (final URL url : ((URLClassLoader) parent).getURLs()) {
System.out.println(url);
}
}
final Class<?> class1 = parent.loadClass(LAUNCH_CLASS);
final Method method = class1.getMethod("launch", String[].class);
final Object[] methodArgs = new Object[] { args };
method.invoke(null, methodArgs);
} catch (final Throwable e) {
e.printStackTrace();
}
}

}

Attachment: build.xml
(Size: 2.23KB, Downloaded 171 times)
Attachment: main.java
(Size: 2.24KB, Downloaded 204 times)